1. Field
The present invention relates to a knife arrangement for minimizing feathering of food products, in particular potatoes, during high speed cutting of the products.
2. Related Art
Food product slicing apparatus is known in which a food product is transported into a rotating wheel having a plurality of cutting knives such that the food product is cut into slices. In the food processing industry, in particular potato chip processing, it is vitally important that the food product be cut into slices having a uniform thickness with minimum or no damage of the food product. Such thickness uniformity facilitates the further processing of the food product giving a maximum amount of usable food product with a minimum amount of waste, and facilitates uniform baking, cooking and frying of the products after slicing of same.
Broadly, food slicing devices comprise those having a rotating wheel in which a plurality of knives extend between a hub and a rim, and the food product is fed through the cutting plane of the rotating wheel, and those having a drum in which the circumference of the drum comprises a plurality of shoes, each shoe having a cutting knife thereon wherein the cutting edge of one shoe is spaced from a trailing edge of an adjacent shoe to control the thicknesses of the sliced food product. In the drum-type of cutting devices, the food product is fed into the interior of the drum onto a rotating base and is driven by paddles or blades on the base and by centrifugal force into contact with the stationary axially extending cutting knives radially projecting towards the drum interior. Generally speaking, controlling the consistency of the thickness of food products sliced with the rotating wheel device requires accurate coordination between the rotating speed of the wheel, the spacing between the blades of the wheel and the feed rate of the food product.
The drum type of slicing apparatus accurately controls the thickness of the sliced food product, but cannot reach the desired high output volume without the possibility of damaging the food product. The output volume of these devices is limited by the rotational speed of the base, which must be limited to prevent possible damage to the food product by contact with the paddles or blades of the base. Another drawback associated with this type of slicing apparatus relates to the orientation of elongated food products. It is often desirable to slice an elongated food product either perpendicular to, or at an oblique angle relative to the longitudinal axis of the elongated food product. However, it is extremely difficult to properly orient elongated food products, which may have varying dimensions, both longitudinally and laterally, in the drum type of slicing apparatus in order to slice the food product in the desired orientation.
Typical, known cutting wheels are illustrated in FIGS. 1 and 2. A first type of known wheel illustrated in FIG. 1 comprises a hub 10, about which is concentrically arranged a rim 12, the hub and rim being interconnected by a plurality of knives 14. Each of the knives 14 has a cutting edge 16 facing in the direction of rotation of the wheel, indicated by arrow 18. The width W of each of the cutting knives 14 is relatively small thereby forming a radially extending space 20 between a trailing edge of one knife and the cutting edge of the adjacent knife having large dimensions in a circumferential direction. Not only is the space 20 between the knives relatively large, but the circumferential dimension of this space 20 is greater adjacent to the rim than adjacent to the hub.
A second type of known cutting wheel is illustrated in FIG. 2 wherein the hub 10 and the rim 12 are similar to the previously described cutting wheel, but cutting knives 22 have a greater width W. Again, the knives 22 each have a cutting edge 24 facing in the direction of rotation, illustrated by arrow 26. Although the radial space 28 between the cutting edge of one knife and a trailing edge of an adjacent knife is somewhat smaller than in the previously described known cutting wheel, the circumferential dimensions of the space 28 varies greatly between the rim and the hub.
Typically, the food product is transported at a food product receiving area through the cutting plane of the cutting wheel at a constant speed and the cutting wheel is rotated, also at a constant speed. The varying circumferential dimensions of the radial spaces 20 and 28 between the adjacent knives 14 and 24 render it difficult to achieve a desired high level of consistency in the thickness of the sliced food product.
Still other prior art knives for slicing food products in a rotary slicing machine are illustrated in FIGS. 3-7, wherein knives 30 that are formed triangular in shape or knives comprising triangular holders 48 supporting separate knife blade elements 50 are used to maintain a constant radial gap between adjacent knives mounted on a cutting wheel.
Still other examples of prior art knives suitable for use in cutting wheels are illustrated in FIGS. 10-19, wherein a gauging surface 70 is provided on the side of a slicing knife facing the uncut food product to control uniformity of slices cut by the knife. For a fuller description of the prior art cutting knives discussed above, reference may be made to U.S. Pat. No. 5,992,284 granted Nov. 30, 1999 and assigned to the owner of the present application. The text and drawings of U.S. Pat. No. 5,992,284 are hereby incorporated by reference in this description.
While the prior art knives incorporating gauging surfaces as described in U.S. Pat. No. 5,992,284 and illustrated in FIGS. 9-19 to be discussed in more detail below produce slices of food product having highly uniform and precise thicknesses, certain hard core food products such as potatoes intended for use in the production of food products such a potato chips or french fries were observed to contain cracks or fissures along the surface of the cut slice facing the cutting edge of the slicing knife, a phenomenon referred to as “feathering” in the food product diminution industry.